JP2001073149A - ECR film forming equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ECR film forming system capable of automatically and instantaneously controlling the power of microwaves. SOLUTION: In an ECR-CVD system provided with two ECR plasma generating parts 4A and 4B arranged with a reaction chamber 2 between, the control deviation of microwave power caused by the variation of film forming pressure is detected by power monitors 7A and 7B, and the control deviation of microwave power is corrected by automatic matching apparatus 6A and 6B. As a result, its instantaneous control is made possible, stable ECR plasma can be obtd., and the producing efficiency improves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ECR film forming apparatus for forming a protective film formed on a magnetic recording medium such as a hard disk or a magneto-optical recording medium.

[0002]

2. Description of the Related Art In a magnetic recording medium such as a hard disk, a magneto-optical recording medium, and a magnetic head, a protective film is formed on the surface for protection from an external environment. This protective film is required to have film characteristics such as wear resistance, voltage resistance and corrosion resistance, and for example, DLC (diamond-like carbon) or the like is used. In the case of a magnetic recording medium, a thin film is formed on a substrate of the recording medium in the order of an underlayer, a magnetic layer, and a protective layer, and a sputtering method is generally used to form the protective film.

The protective film used for a magnetic recording medium or a magnetic head is required to have a smaller thickness in addition to the above-mentioned film characteristics in accordance with performance requirements such as miniaturization, high response and large capacity of the device. Is required. However, the protective film formed by the sputtering method has a thickness of 10
If the thickness is less than about nm, the film properties such as abrasion resistance, voltage resistance, and corrosion resistance are reduced, and there is a problem that the function as a protective film cannot be sufficiently exhibited.

Accordingly, instead of the conventional sputtering method, ECR (elctron cyclotron resonance) -CVD
There has been proposed a method of forming a protective film using a method (Japanese Patent Application Laid-Open Nos. 10-53875 and 10-53877).
No.). According to this ECR-CVD method, a uniform protective film can be formed, and a protective film thinner than that obtained by the sputtering method and having excellent film characteristics can be obtained.

[0005] The ECR-CVD method is a method of generating a plasma of a film forming gas by ECR resonance.
The R discharge state differs depending on the film forming pressure. Therefore, when the pressure in the reaction chamber fluctuates due to the influence of the product adhering to the reaction chamber wall or the sudden fluctuation of the amount of introduced gas, the microscopic control is performed so that the ECR discharge does not become unstable or stop. It is necessary to adjust the wave power.

[0006] Here, the difference [Delta] P = P _f of energy applied to the discharge from the power P _f of the incident wave and power P _r of the reflected wave
Since the observed as -P _r, adjustment of the incident as effective microwave power ΔP is the set value power P _f and the reflected wave power P _r. In a normal device, the incident power _Pf is set to be constant, and a deviation from the set value of the microwave effective power ΔP (hereinafter, this is referred to as a deviation of the microwave adjustment point) is a reflected wave. It is observed as a change in power _Pr .

[0007]

However, in the conventional ECR-CVD apparatus, this adjustment is performed manually. Therefore, when the microwave adjustment point shifts due to the pressure fluctuation, the operator has to perform the adjustment each time. He had to go to the membrane device and make adjustments. Therefore, power adjustment cannot be performed instantaneously with respect to the deviation of the microwave adjustment point, and fine adjustment is difficult. In such an apparatus, there is a problem that stable film formation is not possible during manual adjustment, and the production efficiency is reduced. In particular, when two ECR plasma generators are arranged so as to face each other and film formation is performed on both the front and back surfaces of a substrate as in the apparatus disclosed in Japanese Patent Application Laid-Open No. There has a problem that the value of the interference to each other by P _r is or vibrate slightly shifted, there is a problem that manual not be adjusted.

[0008] An object of the present invention is to provide an ECR film forming apparatus utilizing ECR plasma, which can automatically and instantaneously adjust the power of microwaves especially in double-sided ECR film forming. To provide.

[0009]

An embodiment of the present invention will be described with reference to FIG. (1) The invention according to claim 1 is an ECR in which an electron cyclotron resonance plasma is generated by microwaves from the microwave sources 9A and 9B and a magnetic field generated by the magnetic field generating means 42, and a film is formed using the electron cyclotron resonance plasma.
The above-mentioned object is achieved by providing the film forming apparatus with detecting means 7A and 7B for detecting the deviation of the adjustment of the microwave power and correcting means 6A, 6B, 16A and 16B for correcting the deviation of the adjustment of the microwave power. To achieve. (2) The invention of claim 2 has a magnetic field generating means 42, and the magnetic field generated by the magnetic field generating means 42 and the microwave sources 9A, 9
The present invention is applied to an ECR film forming apparatus including two plasma generating mechanisms 4A and 4B for generating electron cyclotron resonance plasma by using microwaves from B, and two plasma generating mechanisms 4A and 4B are arranged to face each other with the reaction chamber 2 interposed therebetween. Detecting means 7A and 7B for detecting an adjustment deviation of microwave power,
Correction means 6 for correcting the deviation of the adjustment of the microwave power
A, 6B, 16A, and 16B achieve the above object.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to facilitate understanding of the present invention. However, the present invention is not limited to the embodiment.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 3 is a diagram schematically illustrating a film forming process of a hard disk (hereinafter, referred to as HD) which is one of the magnetic recording media. In step 1, the HD substrate is taken into an HD film forming apparatus, and in step 2, the HD substrate is heated. The HD film forming apparatus consists of a plurality of film forming apparatuses,
They are linked in process order. After forming an underlayer on the front and back surfaces of the HD substrate by a sputtering method in step 3, a magnetic layer is formed on the underlayer by a sputtering method in step 4. Next, in step 5, the DLC protective film is
-After forming the film by the CVD method, the substrate is taken out from the HD film forming apparatus in step 6. The steps of forming the underlayer and forming the magnetic layer also include various steps (such as etching and heating) involved in forming the film.

Next, referring to FIGS. 1 and 2, an ECR-CVD apparatus according to an embodiment of the ECR film forming apparatus according to the present invention will be described.
The device will be described. FIGS. 1 and 2 show D in step 5 described above.
FIG. 1 is a view showing a schematic configuration of an ECR-CVD apparatus 1 used for forming an LC protective film, FIG. 1 is a block diagram, and FIG. 2 is an external view. In the ECR-CVD apparatus 1 shown in FIGS.
Reference numeral 2 denotes a reaction chamber into which the HD substrate 3 is loaded. Two reaction chambers 4A and 4B
Are arranged to face each other. The ECR plasma generation section 4A has a plasma generation chamber 41A which is a cavity (for example, having a resonator structure of _TE111 mode) and an electromagnetic coil 42A provided around the plasma generation chamber 41A.
1A has a waveguide 5A, an automatic matching unit 6A, and a power monitor 7.
A, a microwave source 9A is connected via a microwave input unit 8A. Similarly, the ECR plasma generating section 4B also has a plasma generating chamber 41B and an electromagnetic coil 42B. And a microwave source 9A.

Each of the power monitors 7A and 7B includes a power monitor for detecting an incident wave (a microwave incident on the plasma generation chambers 41A and 41B) and a reflected wave (the plasma generation chambers 41A and 41B).
And a power monitor for detecting (the microwave reflected by 41B). 16A and 16B are automatic matchers 6 based on the detection values of the power monitors 7A and 7B.
A and 6B are matching unit control units for controlling
Is a main controller for controlling the entire apparatus.

As shown in FIG. 1, each automatic matching unit 6A, 6
B has three stubs 61a, 61b, and 61c, each of which is provided so as to protrude into the conduit of the matching device. Actuators 62a, 62 for moving the stubs 61a, 61b, 61c in and out of the pipeline are provided.
b and 62c are provided respectively. The driving of the stubs 61a to 61c by the actuators 62a to 62c
The matching devices are controlled by matching unit control units 16A and 16B based on the detection values of power monitors 7A and 7B.

The stubs 61a to 61c and the actuators 62a to 62c shown in FIG. 1 are accommodated in portions of the automatic matching units 6A and 6B shown in FIG. The automatic matching devices 6A and 6B are provided, for example, at 90 ° to each other with respect to the traveling direction of the microwave, and a portion C of the automatic matching device 6B where the stubs 61a to 61c and the actuators 62a to 62c are provided.
B is located as shown by the broken line. In the present embodiment, the deviation of the two automatic matching devices 6A and 6B from the traveling direction of the microwave is set to 90 °, but this value differs depending on the configuration and the pressure of the plasma generation chambers 41A and 41B. It is not limited to 90 °.

As described above, comparing the structures of the devices provided on the left and right sides of the reaction chamber 2 in the drawing, the plasma generation chambers 41A,
Except that the phases of the microwaves input to 41B are shifted from each other by 90 °, the microwaves 9A and 9B have exactly the same function, and the ECR plasma generators 4A and 4B
The configuration up to this point is the same. In the following, regarding the description of this portion, the configuration on the left side of the drawing, that is, the microwave source 9A
To the ECR plasma generator 4A.

As shown in FIG. 1, the reaction chamber 2 is connected to a film forming gas supply device 11 via a mass flow controller (MFC) 12, and is provided with an exhaust pump 13. During the formation of the protective film, the flow rate of the film forming gas supplied to the reaction chamber 2 is maintained at a predetermined value by the MFC 12.
A pressure gauge 14 detects the pressure in the reaction chamber 2, and a detection signal of the pressure gauge 14 is sent to the main controller 10. A negative pulse bias voltage Vb is applied by a bias power supply 15 to the HD substrate 3 loaded in the reaction chamber 2.

As described above, the ECR plasma generator 4
A has a plasma generation chamber 41A and an electromagnetic coil 42A provided around the plasma generation chamber 41A, and active ECR plasma is generated in the plasma generation chamber 41A by ECR resonance. As the ECR resonance conditions at this time, a microwave frequency of 2.45 GHz and a magnetic flux density of 87.5 mT are used. That is, the frequency 2.45 from the microwave source 9A
Automatic microwave matching device 6A and waveguide 5A
And a magnetic field having a magnetic flux density of 87.5 mT is formed in the plasma generation chamber 41A by the electromagnetic coil 42A to generate an ECR discharge.

As shown in FIG. 1, by disposing the two ECR plasma generators 4A and 4B opposite each other so as to sandwich the reaction chamber 2, the divergent magnetic field formed in the reaction chamber 2 is used as a mirror magnetic field to stabilize discharge. Further, the ion flux density distribution near the HD substrate 3 is made uniform, and the film thickness distribution formed on both surfaces of the HD substrate 3 is made uniform. In order to obtain a uniform ion flux density distribution by adjusting the divergent magnetic field, the current applied to the electromagnetic coil 42A is controlled while the ECR conditions in the plasma generation chamber 41A are satisfied, and the plasma is appropriately controlled. Adjust the magnetic field distribution so that it spreads.

The ECR plasma generated in the plasma generation chamber 41A moves toward the HD substrate 3 in the reaction chamber 2 along the divergent magnetic field generated by the electromagnetic coil 42A. The film forming gas ionized in the high-density plasma by ECR forms a thin film on the HD substrate 3 by the negative pulse bias voltage Vb. When a DLC film is formed as a protective film, ethylene (C ₂ H ₄ ), methane (CH ₄ ), propane (C ₃ H ₈ ), or the like is supplied from a film forming gas supply device 11 as a film forming gas.

[0021] As described above, discharge state when performing the ECR deposition is observed as the difference ΔP = P _f -P _r the power P _f of the incident wave and power P _r of the reflected wave, the effective microwave power ΔP affects the film formation. Also, the incident power P _f
Is set to be constant, the deviation of the microwave adjustment point is observed as a change in the reflected wave power _Pr . In the apparatus of the present embodiment, the stub 61 is driven by driving the actuators 62a, 62b, 62c of the automatic matching units 6A, 6B.
a, 61b, by adjusting the amount of projection of 61c, and to perform shift correction microwave adjustment points by performing matching adjustment of the reflected wave power P _r.

Next, the procedure for correcting the deviation of the microwave adjustment point will be described with reference to the flowcharts of FIGS. The flowchart of FIG.
This shows a film forming process from when the D substrate 3 is loaded to when the film formation of the protective film is completed. When the HD substrate 3 is loaded in the reaction chamber 2, the supply of the film forming gas to the reaction chamber 2 is started in step S1. Then, step S
At 2, the power sources of the microwave sources 9A and 9B are turned on.

[0023] Step S3 is a step of determining whether power monitor 7A, the incident wave power P _f detected by the 7B is preset threshold P _f0 above, P _f ≧ P _f0
And until it is determined repeatedly executes processing in step S3, if it is determined that P _f ≧ P _f0 proceeds to step S4.
In step S4, the incident wave power P _f and the reflected wave power P _f
FIG. 5 shows an example of this routine.

In FIG. 5, the processing of steps S10 to S12 corresponds to the incident wave power adjustment.
The processes from 13 to S15 correspond to the reflected wave power adjustment. In step S10, the power monitors 7A and 7B
Detecting the incident wave power P _f by. Step S11
Is, when the detected incident wave power P _f is determining whether to satisfy the following equation (1) with respect to the incident wave power set value P _{f The set,} it is determined that YES step S13
The process proceeds to step S12 if NO is determined.

P _fset −ΔP ≦ P _f ≦ P _fset + ΔP (1) When the process proceeds from step S11 to step S12,
Performs power adjustment of the microwave source 9A, 9B so that the incident wave power P _f satisfies Equation (1) in step S12, the flow returns to step S10.

On the other hand, from step S11 to step S13
If the procedure advances to detect the reflected wave power P _r power monitor 7A, by 7B in step S13. Step S14 is a step of determining whether or not to satisfy the following equation (2) for the detected reflected wave power P _r is the reflected wave power set value P _rset, when it is determined that the NO to the step S15 The process proceeds to YES at step S5 if YES.

[Number 2] In the case of proceeds from _{P rset -ΔP ≦ P r ≦ P} rset + ΔP ... (2) step S14 to step S15,
Performs matching adjustment of the reflected wave power P _r by automatic matching box 6A, 6B as the reflected wave power P _r satisfies the formula (2) in step S15, the flow returns to step S13.

Returning to FIG. 4, step S5 is a step for determining whether or not the predetermined film formation has been completed. If YES is determined, the process proceeds to step S6, and if NO is determined, the process returns to step S4. . In other words, until completion from the start of film formation, the reflected wave power P _r power monitor 7A, the 7B
Monitor constantly and make adjustments as needed. Here, when judging the end of the film formation, the microwave sources 9A, 9
The elapsed time since the power supply of B was turned on, that is, the time from step S2 to step S5 is measured by a timer or the like, and it is determined whether or not the film formation time has reached the set time. When the process proceeds from step S5 to step S6 after a predetermined film forming time has elapsed, the power of the microwave sources 9A and 9B is turned off in step S6. Thereafter, the process proceeds to step S7, in which the supply of the deposition gas is stopped. Thus, a series of film forming processes is completed.

When two ECR plasma generators 4A and 4B are provided so as to face each other with the reaction chamber 2 interposed therebetween as in the apparatus of the present embodiment, the light is reflected by the power monitors 7A and 7B. When a wave is detected, the microwave from the other ECR plasma generating unit has an effect. Therefore, when the required accuracy of the deviation correction is high, the automatic matching unit 6
A (6B), the other automatic matching unit 6
It is preferable to control so that the correction amount of B (6A) is fed back. However, if the required accuracy is not so high, the left and right automatic matching units 6A and 6B may be controlled independently.

As in the present embodiment, the automatic matching devices 6A,
The apparatus for correcting the deviation of the microwave adjustment point using 6B has the following advantages. The first advantage is that when a shift of the microwave adjustment point occurs due to a change in the film forming pressure, the shift is automatically corrected by the automatic matching units 6A and 6B. (Seconds or less), and fluctuations in film forming conditions can be suppressed. On the other hand, for example, when adjusting the stub manually, the operator goes to the apparatus after confirming the change in the film forming pressure, and operates the stubs of the two matching devices while checking the power monitor. There is a need to. Therefore, it is not possible to respond quickly to a change in the film forming pressure, and it is not possible to respond to a stop of discharge or a short-time change.

At present, the production efficiency of HD is about 600 sheets / hr, and the time for one process is very short, about 6 seconds. It is said that it will be about one sheet / hr. For this reason, in the manual adjustment apparatus, a considerable number of HD substrates 3 are formed under unstable film forming conditions until the deviation is corrected, which causes a reduction in production efficiency. On the other hand, with the film formation apparatus of this embodiment, film formation conditions can be stabilized, and a decrease in production efficiency can be prevented.

The second advantage is that the actuators 62a to 62c are used for driving the stubs 61a to 61c.
Positioning can be performed with higher precision than when the operator manually operates the stub, and accurate power adjustment can be performed. As a result, a thin and uniform film can be repeatedly formed with high precision in mass production. In particular, in the case of a protective film, it is effective because the demand for thinning is high.

In the above-described embodiment, two ECR plasma generators 4A and 4B are provided with the reaction chamber 2 interposed therebetween.
The present invention can be applied to an apparatus provided with only one ECR plasma generating unit, such as an ECR film forming apparatus disclosed in Japanese Patent Application Laid-Open No. 10-53877. However,
As described above, in the case of an apparatus having two ECR plasma generators, the adjustment is delicate due to the influence of the microwave from one ECR plasma generator, and the automatic matching units 6A and 6B are provided. The effect of this is enormous. Further, the present invention is not limited to the ECR-CVD film forming apparatus.
An apparatus for forming a film using R plasma, for example, ECR
The present invention can also be applied to a sputtering apparatus and the like.

In the correspondence between the above-described embodiment and the elements of the claims, the power monitors 7A and 7B are provided with detecting means for automatically matching units 6A and 6B and the matching unit control unit 1.
Reference numerals 6A and 16B denote correction means and electromagnetic coils 42A and 42B.
Represents a magnetic field generating means, and the ECR plasma generating sections 4A and 4B constitute a plasma generating mechanism.

[0033]

As described above, according to the present invention,
If the film forming pressure fluctuates and a microwave power adjustment shift occurs, the adjustment means automatically corrects the shift. As a result, instantaneous adjustment becomes possible, and a decrease in production efficiency due to unstable plasma discharge can be suppressed, and a highly accurate deviation correction can be made.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ECR-CVD apparatus according to the present invention.

FIG. 2 is an external view of an ECR-CVD apparatus.

FIG. 3 is a view schematically showing an HD film forming process.

FIG. 4 is a flowchart showing a film forming process.

FIG. 5 is a flowchart showing details of a routine of step S4 in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ECR-CVD apparatus 2 Reaction chamber 3 HD substrate 4A, 4B ECR plasma generation part 5A, 5B Waveguide 6A, 6B Automatic matching device 7A, 7B Power monitor 9A, 9B Microwave source 10 Main controller 11 Film forming gas supply device 14 Pressure gauge 16A, 16B Matching device control unit 41A, 41B Plasma generation chamber 42A, 42B Electromagnetic coil 61a-61c Stub 62a-62c Actuator

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoshio Takami 1-term, Kuwabaracho, Nishinokyo, Nakagyo-ku, Kyoto F-term in Shimadzu Corporation (reference) 4K030 AA09 AA10 BA28 FA02 KA39 KA41 LA20 5D075 EE03 FG04 GG02 GG12 5D112 AA07 AA24 FA10

Claims (2)

[Claims] 1. An ECR film forming apparatus for generating an electron cyclotron resonance plasma by using a microwave from a microwave source and a magnetic field generated by a magnetic field generating means, and performing film formation using the electron cyclotron resonance plasma. An ECR film forming apparatus comprising: a detection unit that detects an adjustment deviation; and a correction unit that corrects the adjustment deviation of the microwave power. 2. A magnetic field generating means, comprising two plasma generating mechanisms for generating an electron cyclotron resonance plasma by a magnetic field generated by the magnetic field generating means and a microwave from a microwave source, wherein the two plasma generating mechanisms react. An ECR film forming apparatus comprising: an ECR film forming apparatus which is arranged to face each other across a chamber, comprising: a detecting means for detecting an adjustment shift of microwave power; and a correcting means for correcting the adjustment shift of microwave power. apparatus.